FTA Cards
(Flinders Technology Associates)
The chemically-impregnated paper cards that revolutionised DNA collection, preservation, and forensic analysis worldwide.
1. What Are FTA Cards?
FTA cards — short for Flinders Technology Associates cards — are specialized, chemically-impregnated cellulose (filter paper) cards engineered to collect, preserve, and transport biological samples for nucleic acid analysis. Whether the sample is blood, saliva, buccal cells, semen, or even plant or animal tissue, FTA cards capture it, instantly lyse the cells, denature harmful proteins, and lock DNA into the paper matrix for long-term, room-temperature storage.
Today, they are commercially produced and marketed primarily by Whatman® (now owned by Cytiva / GE Healthcare) and QIAGEN, under names like Whatman FTA Classic, Whatman FTA Elute, QIAcard FTA Indicating, and more. They are indispensable tools in forensic science, clinical diagnostics, biobanking, wildlife genetics, newborn screening, and infectious disease surveillance.
2. History & Origin
The story of FTA cards begins in the 1980s in Australia. Scientists Dr. Lee Burgoyne and Fowler at Flinders University in South Australia were looking for a simple, practical method to protect DNA samples from the rapid degradation caused by nucleases, UV light, oxidation, and microbial contamination — all constant threats in field and clinical conditions.
Their solution was elegantly simple: apply a mixture of a weak base, a chelating agent (EDTA), an anionic surfactant/detergent, and uric acid (or a urate salt) to a cellulose-based filter paper. This treated paper could accept biological samples, immediately stabilise the nucleic acids within them, and allow safe, ambient-temperature storage and transport.
The technology was patented under the name "Flinders Technology Associates" — giving FTA cards their name. Whatman® International Ltd., UK subsequently licensed the FTA® technology from Flinders University and commercialised it globally. Over the decades, the technology evolved to include different card formats for different downstream analyses, and today QIAGEN also distributes a full line of QIAcard FTA products.
⚗ Did You Know?
FTA® is also sometimes interpreted as "Fast Technology for Analysis of nucleic acids" — reflecting the technology's speed advantage in sample processing workflows, particularly for PCR-based applications.
3. Chemistry & How They Work
The power of FTA cards lies in their patented chemical cocktail impregnated into the cellulose matrix. Here is what each component does when a biological sample contacts the card:
🔬 Chemical Composition
| Component | Role |
|---|---|
| Weak Base (e.g., guanidine thiocyanate / chaotropic salt) | Lyses cells and organelles on contact; denatures proteins irreversibly |
| Chelating Agent (EDTA) | Binds metal ions that activate DNase enzymes, thereby inhibiting DNA degradation |
| Anionic Detergent / Surfactant (SDS) | Further disrupts cell membranes; assists in lysing cells and solubilising proteins |
| Uric Acid / Urate Salt | Acts as a free-radical scavenger — neutralises reactive oxygen species that would otherwise oxidise and fragment DNA |
⚙️ Mechanism of Action
When a biological sample — say, a blood drop — is applied to an FTA card, the following cascade occurs almost instantaneously:
- Cell Lysis: The chemical denaturants rupture cells and organelles, releasing their DNA content into the paper matrix.
- Protein Denaturation: Proteins — including nucleases (the enzymes that destroy DNA) — are irreversibly denatured and rendered inactive. They remain permanently immobilised in the card matrix.
- DNA Capture: The released DNA becomes physically entangled and chemically bound within the cellulose fibres. In Classic cards, DNA binds tightly and permanently. In Elute cards, DNA binds reversibly and can be released later.
- Pathogen Inactivation: Viruses, bacteria, fungi — all biological hazards in the sample — are inactivated within seconds, making the dried card biologically safe to handle and ship.
- Long-Term Stabilisation: Once dried at room temperature, the card protects DNA from nuclease activity, UV damage, oxidation, and microbial growth for years to decades.
4. Types of FTA Cards
The Whatman/QIAGEN FTA product line offers several card variants, each optimised for specific applications:
| Card Type | Mechanism | DNA Binding | Best For |
|---|---|---|---|
| FTA Classic Card | Permanent chemical binding of DNA to matrix | Tight (non-releasable without special protocol) | Forensic reference samples, STR profiling, PCR direct amplification |
| FTA Elute Card | Reversible DNA binding; DNA eluted by heating in water/buffer at 95°C | Reversible (releasable) | Whole-genome sequencing, high-throughput applications, STR, real-time PCR |
| FTA Indicating Card | Contains a colour-change indicator dye (pink/purple → white on sample contact) | Classic or Elute variant | Buccal cells, saliva; visual confirmation of sample deposition |
| FTA Micro Card | Single sample area per card | Elute variant | Individual reference samples, paternity testing, forensic ID |
| FTA CloneSaver Card | 96-well format for bacterial colonies | Permanent | Plasmid/BAC DNA storage, microbial genomics |
The Indicating cards are particularly useful in forensic and clinical settings because the colour indicator (often purple or pink) turns white upon contact with a sample, providing immediate visual confirmation that the collection was successful.
5. Step-by-Step: How to Use FTA Cards
Using FTA cards correctly is essential for ensuring the integrity of the sample. Below is the standard protocol used in forensic and clinical settings:
🩸 Step 1 — Sample Collection
Prepare the Card
Label the FTA card with the sample ID, date, case number, and collector's name before sample application. Never touch the sample area with bare hands — use gloves throughout.
Apply the Biological Sample
Apply the sample directly onto the designated circle(s) on the card. For blood: apply a drop (up to 40 µL per circle) directly or from a swab/lancet. For buccal cells/saliva: rub a foam swab or the EasiCollect device against the inner cheek and press onto the card. For semen: apply directly or transfer from a swab. Liquid samples should fill but not overflow the sample circle.
Observe the Indicator (if using Indicating Card)
On Indicating cards, watch for the colour change from pink/purple to white, which confirms the sample has been successfully deposited and the chemistry has been activated.
Air Dry the Card
Allow the card to air dry completely at room temperature — typically 1–3 hours. Alternatively, dry at 80°C for 15–20 minutes in an oven. Do not seal or cover a wet card, as moisture promotes mould growth. The card must be completely dry before storage or shipment.
Package for Storage or Transport
Once fully dry, place the card in the provided multi-barrier pouch or a desiccant-containing bag. Seal securely. Store at room temperature in a cool, dry, dark location. FTA Card Mailers are available for U.S. Postal Service-compliant shipping. No dry ice or refrigeration is required.
6. DNA Extraction Methods from FTA Cards
There are three primary approaches to accessing DNA stored on FTA cards, depending on the card type and downstream application:
Method A — Direct Amplification ("Punch-In" Method) — FTA Classic
This is the fastest method, used most commonly in forensic STR profiling:
- Use a Harris Uni-Core micropunch (1.2 mm–6.0 mm diameter) to cut a small disc from the centre of the dried sample spot.
- Place the disc in a clean, RNase/DNase-free microcentrifuge tube.
- Wash the disc twice with FTA Purification Reagent (200 µL each, 5 minutes at room temperature) to remove cellular debris, haemoglobin, and PCR inhibitors.
- Wash twice with TE buffer (10 mM Tris, 0.1 mM EDTA) to remove residual purification reagent.
- Air dry the disc on a heat block at 56°C for 15 minutes.
- Add the washed, dried punch directly into the PCR reaction mix. The DNA on the punch serves as the template.
Method B — DNA Elution — FTA Elute Card
- Punch a 1–8 mm disc from the sample area.
- Wash the disc once with QIAcard FTA Wash Buffer.
- Add 200 µL of sterile water or QIAcard FTA Elute Buffer.
- Incubate at 95°C for 20–30 minutes. Heat releases DNA from the matrix by breaking the reversible binding.
- Vortex briefly, centrifuge, and collect the supernatant containing eluted DNA.
- Use the eluted DNA for PCR, sequencing, STR analysis, or other downstream applications.
Method C — Organic Extraction
For applications requiring high molecular weight (HMW) DNA (e.g., whole-genome sequencing, epigenetic studies):
- Prepare extraction buffer: 10 mM Tris-HCl (pH 8.0), 10 mM EDTA, 100 mM NaCl, 2% SDS.
- Add 500 µL of extraction buffer + 20 µL of Proteinase K (20 mg/mL stock) to the card punch in a microcentrifuge tube.
- Vortex and incubate at 56°C overnight with agitation.
- Add equal volume of buffered phenol (pH 8.0), vortex briefly, centrifuge 10 min at max speed.
- Collect the aqueous phase; repeat phenol-chloroform extraction if needed.
- Precipitate DNA with ethanol, wash pellet with 70% ethanol, air dry, resuspend in TE buffer.
7. Applications in Forensic Science & Beyond
🔍 Forensic Genetics
FTA cards are used to collect reference DNA samples from suspects, victims, and offenders for national DNA databases (such as CODIS in the USA). Biological fluids — blood, saliva, semen — can be collected at the scene or from individuals and preserved on FTA cards, then processed for STR (Short Tandem Repeat) profiling, the gold standard of forensic DNA identification.
🏥 Newborn Screening
Dried blood spots (DBS) on filter paper cards (often FTA-based) are the universal method for neonatal heel-prick blood collection. These samples are archived and used for metabolic disorder screening and, increasingly, whole-genome sequencing studies.
🦠 Infectious Disease & Virology
FTA cards inactivate pathogens on contact, making them ideal for safely collecting and transporting samples from HIV, SARS-CoV-2, rabies, avian influenza, and other dangerous pathogens for PCR-based detection, without the biohazard risks of liquid biological specimens.
🐾 Wildlife & Conservation Genetics
Researchers use FTA cards in remote field conditions — where cold-chain infrastructure is unavailable — to collect blood or tissue from wild animals, endangered species, and livestock for genetic characterisation and population studies.
🔬 Epigenetics & Genomics
Recent research has demonstrated that FTA elute cards can preserve DNA methylation marks, opening the door for epigenomic studies from archival samples stored at room temperature for over a decade.
⚖️ Paternity & Human Identity Testing
Buccal swabs collected on FTA Indicating cards are a standard method for paternity and kinship testing, offering a non-invasive, room-temperature-stable specimen collection method.
🌿 Plant & Microbial Genomics
Plant leaf tissue, microbial cultures, and food samples can be applied directly to FTA cards for pathogen detection, species identification, and GMO testing using PCR.
8. Advantages of FTA Cards
- No Cold Chain Required: DNA stored on FTA cards is stable at ambient room temperature for 10–20+ years, eliminating costly refrigeration or cryogenic storage.
- Instant Biohazard Inactivation: Pathogens are neutralised within seconds of sample contact, ensuring safe handling and compliant postal shipping.
- Simple Collection Protocol: Minimal training is required; samples can be collected by non-specialist personnel in the field, clinic, or crime scene.
- Direct-to-PCR Compatibility: For Classic cards, no DNA extraction is needed — the washed card punch can go directly into a PCR tube, saving time and reducing contamination risk.
- Cost-Effective: Compared to DNA extracts stored frozen, FTA card storage is significantly cheaper for large-scale biobanking or database operations.
- High-Throughput Compatible: Cards can be processed in 96-well plate formats for automated forensic workflows, with run times as low as 30 minutes per plate.
- Archival Re-Analysis: Samples stored on FTA cards can be re-analysed months or years later as newer technologies become available.
- Lightweight & Portable: Ideal for remote fieldwork, mass disaster operations, and developing-country settings where laboratory infrastructure is limited.
9. Limitations & Challenges
- Low Molecular Weight DNA: Standard FTA protocols, particularly heat-based elution from Elute cards (95°C), fragment DNA, limiting suitability for whole-genome sequencing applications requiring long reads.
- Irreversible Binding (Classic): DNA on Classic cards is permanently bound; elution requires specialised protocols that may not recover all material.
- Inhibitors May Co-elute: Haemoglobin and other PCR inhibitors, if not fully washed out, can reduce PCR efficiency and affect STR profiling quality.
- RNA Instability: While FTA Classic cards can preserve RNA for up to ~2 years (with TRIzol extraction), RNA stability is inferior to DNA stability on these cards.
- Limited Epigenetic Studies (Classic): The permanent binding of DNA in Classic cards poses challenges for bisulfite-based methylation analysis, though recent protocols are overcoming this.
- Card Saturation: Applying too much sample can saturate the card and cause overflow, reducing recovery efficiency.
- Requires Complete Drying: Inadequate drying before storage can promote mould growth and DNA degradation — a critical failure point in field conditions.
10. FTA Cards vs. Swabs: A Comparison
| Parameter | FTA Cards | Traditional Swabs |
|---|---|---|
| DNA Stability | ✅ Stable 10–20+ years at room temperature | ❌ Degrades without refrigeration; requires -20°C for long-term |
| Pathogen Safety | ✅ Pathogens inactivated on contact | ❌ Infectious material remains viable |
| Shipping | ✅ Safe, ambient temperature postal shipping | ❌ Requires cold chain or special biohazard packaging |
| PCR Readiness | ✅ Direct-to-PCR (Classic); no extraction needed | ❌ Full DNA extraction required before PCR |
| Cost (Storage) | ✅ Low (no freezers) | ❌ Higher (cold storage infrastructure) |
| DNA Yield | ⚠️ Limited to card punch area | ✅ Can yield more DNA from a single swab |
| HMW DNA | ⚠️ Challenging with standard protocols | ✅ Better yields with organic extraction |
| Field Use | ✅ Excellent — no equipment needed | ⚠️ Possible but storage is problematic |
| STR Profiling | ✅ Well-validated, widely used | ✅ Well-validated |
11. Future Trends & Recent Research
FTA card technology is actively evolving beyond its original PCR-focused applications. Exciting recent developments include:
- Whole-Genome Sequencing from Archived Cards: Researchers have demonstrated scalable, high-quality WGS from archived newborn dried blood spots on FTA-type cards, enabling retrospective genomic studies.
- Epigenetic Preservation: A 2025 study confirmed that DNA methylation marks are preserved on FTA elute cards even after >10 years of ambient storage, enabling epigenomic research from historical specimens.
- COVID-19 Applications: QIAGEN developed protocols showing FTA Elute Indicating cards can collect, stabilise, and enable sensitive PCR detection of SARS-CoV-2 RNA in saliva samples, with RNA stability demonstrated at 20°C and 30°C for up to 7 days.
- Postmortem Forensics: Studies have validated FTA cards for acquiring DNA profiles from postmortem blood samples, outperforming some conventional methods in preservation quality.
- Wildlife Forensics: Non-lethal sampling from gastropods, reptiles, and birds using FTA cards is emerging as a conservation-compatible tool for species identification and population genetics.
12. Conclusion
FTA cards represent one of the most impactful innovations in biological sample management of the past four decades. Born from a simple but brilliant idea at Flinders University in the 1980s, these chemically-treated paper cards have become global workhorses of forensic science, clinical diagnostics, biobanking, and field biology.
For the aspiring forensic scientist, understanding FTA cards is not optional — it is fundamental. From the collection of a reference blood sample from a suspect to the long-term archiving of DNA databases, FTA cards underpin the reliability of the entire forensic genetics pipeline. Their ability to preserve evidence safely, cheaply, and without electricity or cold storage makes them indispensable in both state-of-the-art forensic labs and resource-limited field conditions alike.
As sequencing technologies continue to advance, FTA card protocols are adapting too — and the next decade is likely to see these cards become platforms not just for STR profiling, but for whole-genome and epigenomic forensic intelligence.
📚 Sources & References
- National Institute of Justice (NIJ) — DNA Extraction and Quantitation for Forensic Analysts: FTA® Technology.
https://nij.ojp.gov/ ... /ftar-technology - Gerber L., Whiteley S.L., et al. (2025). Stable preservation and recovery of methylation marks from FTA elute cards. PLOS ONE.
https://pubmed.ncbi.nlm.nih.gov/40743112/ - Namaa et al. (2024). Cryopreservation of Seminal Fluid: FTA-card vs. Swab for STR Analysis. Iraqi Journal of Science, 65(7).
https://www.researchgate.net/publication/382754112 - Montelius K. et al. (2019). Use of FTA cards to acquire DNA profiles from postmortem cases. PubMed.
https://pubmed.ncbi.nlm.nih.gov/30747256/ - QIAGEN — QIAcard FTA Indicating Cards Product Page.
https://www.qiagen.com/ ... /indicating-fta-cards - Sigma-Aldrich / Merck — Reliable DNA Extraction from Whatman™ FTA Cards. Protocol Document.
https://www.sigmaaldrich.com/ ... /whatman-reliable-extraction-of-dna - Sigma-Aldrich — Genomic DNA Purification from Sample on FTA Elute. Protocol.
https://www.sigmaaldrich.com/ ... /genomic-dna-purification-from-sample-on-fta-elute - Tritech Forensics — FTA Card Product Catalogue.
https://tritechforensics.com/fta-card-multiple-size-options/ - Dash H.R., Shrivastava P., Das S. (2020). Reliable Use of Whatman™ FTA™ Cards for One-Step Collection and Isolation of DNA. In: Principles and Practices of DNA Analysis. Springer Protocols.
https://link.springer.com/protocol/10.1007/978-1-0716-0274-4_14 - Review: FTA Cards as a tool for viral RNA preservation in fieldwork. PMC / NCBI.
https://pmc.ncbi.nlm.nih.gov/articles/PMC7126379/ - Use of FTA® Classic Cards for epigenetic analysis of sperm DNA. BioTechniques.
https://www.tandfonline.com/doi/full/10.2144/btn-2017-0101 - SLAS Technology — Automated Forensic DNA Purification for FTA Card Punches and Identifiler STR Analysis (2005).
https://www.slas-technology.org/article/S1535-5535(05)00120-6/fulltext
